The invention described herein relates to a process for endless-cycle sterilization of the sheet material utilized for packaging pre-sterilized fluids in aseptic conditions, and sets forth plant for the purpose.
In the packaging processes normally emoloyed for pre-sterilized products such as milk, juices, &c., it is usual to find a continuous belt, or sheet of material consisting--generally speaking--of a number of layers of paper, synthetic film, super-thin metallic membrane and the like, whose edges are heat-sealed together so as to form a tube with which to fill the already sterilized fluid product. With the tube thus created, single packs are then formed containing the requisite quantity of fluid. It will be clear enough that the tube, which must then come into contact with the pre-sterilized product, will need to be sterile likewise, so as to enable the fluid's being preserved in good condition for an appreciable length of time.
In order to bring about sterilization of the continuous sheet thus used in packaging foodstuffs, one has an existing process which is chemical by definition, and consists in an initial dampening of the sheet in a chemical sterilizer, followed by its being warmed in such a way as to bring about the evaporation of the sterilizer and produce a reaction which duly sterilizes the sheet by chemical means. This particular process is less than satisfactory, since it is extremely difficult to remove all traces of the chemical sterilizer--which tend to appear in the packaged contents on subsequent inspection.
One object of the invention described herein is that of providing a sterilization process, and plant therefor, which involves no use whatever of chemical substances for bringing about sterilization of the sheet material, and which at the same time avoids any disturbance to the properties of the material itself needing sterilization.
A further object of the invention is that of embodying plant for carrying out the process as set forth, whose construction will be characterized by extreme simplicity and economy, and whose actual function will likewise be simple in the extreme.